SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e6df9f47998c764b1189bfc698310db575ef4b571bdb352ea7afeb7593aa33' 
  AND token = 'NPcXU4kv0sldDT5Q5GOVAv6wxzKXFJ/9j/BsjkLOAY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}